1. Field of the Invention
This invention relates to a paper feeding device having a replaceable paper conveying roller, in particularly, to a replaceable paper conveying roller for paper feeding devices such as a scanner, a printer, a fax machine, or a copier.
2. Brief Description of Related Art
Prior art has used a roller to convey papers in a paper feeding device, as shown in FIG. 1. A back shell 16 wraps around two brackets 11 and 12, which reinforce the shell. The brackets 11 and 12 have two sockets 112 and 122 respectively for mounting a shaft 15. A roller 16, made of friction material, is mounted over the shaft 15. The left end 18 of the shaft 15 feeds through the socket 112, and the right end 19 of the shaft 15 feeds through the socket 122. The shaft 15 is indirectly driven by a gear 17 located at the right end of the shaft 15. When the gear 17 is driven by a motor (not shown), the roller 16 rotates and the friction coveys the paper P forward.
Due to high-speed operation of modern paper feeding devices, the roller 16 experiences wear and tear. The lifetime of the paper feeding device is thus adversely affected.
An object of this invention is to increase the useful lifetime of a paper feeding device. Another object is to reduce the servicing cost of a paper feeding device.
These objects are achieved by using a replaceable paper conveying roller for a paper feeding device. A paper feeding device of the invention includes a back plate, a first bracket, a second bracket, a shaft, and a friction roller. The first bracket is arranged on the back plate and formed of a first socket. The second bracket is arranged on the back plate and formed of a second socket. The shaft has a first end and a second end opposite to the first end. The first end of the shaft is rotatably mounted in the first socket. The second end of the shaft is rotatably mounted in the second socket. At least one of the first and second sockets is an open-ended socket for facilitating both the insertion and removal of the shaft. The friction roller wraps around the shaft for conveying a piece of paper.